What this snippet does
Regular functions in callbacks get their own this (usually undefined in strict mode); arrow functions inherit this from the class.
Expected output
broken: NaN fixed: 1
Why practise typing this
Typing objects code builds muscle memory for the symbols and indentation JavaScript uses most, which prose-based typing tests never cover. DevType measures your words per minute and accuracy on this snippet and tracks the individual characters you mistype, so later lessons can target them.
More JavaScript practice
- object literalsObjects · beginner
- computed keysObjects · intermediate
- getters/settersObjects · intermediate
- object iterationObjects · beginner
- object transformObjects · intermediate
- Object.freezeObjects · intermediate